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- railway track
- kinematic characteristics
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- control system
- depth of field
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Spatial and Temporal Properties of SMOS Retrieval Over Tropical Forests
摘要： In this paper, retrieval results obtained using the last version (V650) of SMOS level 2 algorithms are tested considering pixels of Africa and South America. Yearly average values of vegetation optical depth are compared against forest height estimates at continental scale. For selected areas of African woody savannah, multitemporal trends of SM and VOD are compared against environmental variables available from Climatic Research Unit data base.
关键词： Soil Moisture,Forests,Vegetation Optical Depth,SMOS
更新于2025-09-23 15:21:01
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Frequency-Dependence of Vegetation Optical Depth-Derived Isohydriciy Estimates
摘要： Passive microwave radiometry-derived vegetation optical depth measurements can be used to map how different ecosystems are sensitive to drought. This is quantified using the plant physiological concept of isohydricity. VOD-derived effective ecosystem-scale isohydricity maps have recently become commonly used, but their sensitivity to the underlying VOD datasets is not yet well understood. In this work, the dependence of the isohydricity calculation on assumptions about canopy cover penetration - which depends on frequency - and observation time - which varies by sensor in a manner roughly consistent with the observation frequency - are reviewed, and isohydricity datasets from different VOD datasets are compared and validated.
关键词： SMAP,AMSR-E,Isohydricity,vegetation optical depth
更新于2025-09-23 15:21:01
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A Fast 2D-to-3D Image Conversion System based on Depth from Defocus
摘要： Blur variation in 2D images caused by camera focus provides a suitable cue for depth estimation. Depth from defocus (DFD) technique calculates the blur amount in images considering that the depth and defocus blur are related to each other. Conventional DFD methods use only defocused images that might yield low-quality depth data and reconstructed infocused image. In this article, a new DFD methodology based on infocused and defocused images is proposed in which using an infocused image can solve the quality degradation problems. In this method, Subbarao’s DFD is combined with a novel edge blur estimation method to obtain an improved depth map. In addition, a saliency map mitigates the ill-posed problem of depth estimation in homogeneous regions. For real-time full high de?nition (Full-HD) image processing, a parallelized graphics processing unit (GPU) implementation is devised to improve execution speed.
关键词： saliency map,GPU implementation,edge blur estimation,Depth from defocus,2D-to-3D conversion
更新于2025-09-23 15:21:01
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Bremsstrahlung x-ray generation for high optical depth radiography applications on the National Ignition Facility
摘要： We have tested a set of x-ray sources for use as probes of highly attenuating, laser-driven experiments on the National Ignition Facility (NIF). Unlike traditional x-ray sources that optimize for a characteristic atomic transition (often the n = 2 → n = 1 transition in ionized, He-like atoms), the design presented here maximizes the total photon ?ux by optimizing for intense, broadband Bremsstrahlung radiation. Three experiments were performed with identical targets, including a uranium x-ray source foil and a tungsten substrate with a narrow (25 μm wide) collimating slit to produce a quasi-1D x-ray source. Two experiments were performed using 12 beams from the NIF laser, each delivering approximately 46 kJ of laser energy but with different laser spatial pro?les. This pair yielded similar temporal x-ray emission pro?les, spatial resolution, and inferred hot electron temperature. A third experiment with only 6 beams delivering approximately 25 kJ produced a lower hot electron temperature and signi?cantly lower x-ray ?ux, as well as poorer spatial resolution. The data suggest that laser pointing jitter may have affected the location and intensity of the emitting plasma, producing an emission volume that was not well centered behind the collimating slit and lower intensity than designed. However, the 12-beam design permits x-ray radiography through highly attenuating samples, where lower energy line-emission x-ray sources would be nearly completely attenuated.
关键词： high optical depth radiography,laser-driven experiments,Bremsstrahlung radiation,x-ray sources,National Ignition Facility
更新于2025-09-23 15:21:01
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An Evaluation of MODIS-Retrieved Aerosol Optical Depth over AERONET Sites in Alaska
摘要： The air quality monitoring network in Alaska is currently limited to ground-based observations in urban areas and national parks, leaving a large proportion of the state unmonitored. The use of Moderate Resolution Imaging Spectroradiometer MODIS aerosol optical depth (AOD) to estimate ground-level particulate pollution concentrations has been successfully demonstrated around the world and could potentially be used in Alaska. In this work, MODIS AOD measurements at 550 nm were validated against AOD derived from two ground-based Aerosol Robotic Network (AERONET) sunphotometers in Alaska, located at Utqiagvik (previously known as Barrow) and Bonanza Creek, to determine if MODIS AOD from the Terra and Aqua satellites could be used to estimate ground-level particulate pollution concentrations. The MODIS AOD was obtained from MODIS collection 6 using the dark target Land and Ocean algorithms from years 2000 to 2014. MODIS data could only be obtained between the months of April and October; therefore, it was only evaluated for those months. Individual and combined Terra and Aqua MODIS data were considered. The results showed that MODIS collection 6 products at 10-km resolution for Terra and Aqua combined are not valid over land but are valid over the ocean. Note that the individual Terra and Aqua MODIS collection 6 AOD products at 10-km resolution are valid over land individually but not when combined. Results also suggest the MODIS collection 6 AOD products at 3-km resolution are valid over land and ocean and perform better over land than the 10-km product. These findings indicate that MODIS collection 6 AOD products can be used quantitatively in air quality applications in Alaska during the summer months.
关键词： Alaska,Aerosol Optical Depth,Moderate Resolution Imaging Spectroradiometer,Aerosol Robotic Network,air quality
更新于2025-09-23 15:21:01
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Photoreceptor projection from a four-tiered retina to four distinct regions of the first optic ganglion in a jumping spider
摘要： Jumping spiders have four pairs of eyes (ocelli) of which only the principal eyes (PEs) are used to detect features of objects. Photoreceptors in the retina of the PEs form four layers (PL1-4) and terminate in the first optic ganglion (FOG). Here we focus on Hasarius adansoni because it has unique depth vision besides color vision and its FOG appears to contribute to the initial processing of these visual modalities. We first investigated the neuroanatomical organization of the FOG. The three-dimensional structure of the FOG revealed by synapsin immunostaining is horseshoe-shaped and consists of four terminal zones (TZ1-4). Then we traced single photoreceptors through serial sections and found that green-sensitive receptors of PL1 and 2 terminate in TZ1 and 2, respectively, by keeping retinotopic organization. In contrast to TZ1 and 2, TZ3 receives terminals of ultraviolet-sensitive receptors from lateral regions of both PL3 and 4, while photoreceptors of the medial region of PL3 and 4 terminate in TZ4. We further studied details of photoreceptor terminals and the branching pattern of interneurons in the FOG in Golgi stained preparations. Photoreceptors have long lateral processes in each terminal zone. Some photoreceptors terminating in TZ3 have branches innervating TZ1, indicating that TZ1 receives different spectral information. A type of interneuron connects TZ1 and 2, while others have branches within a single terminal zone or in the entire FOG. These results suggest that TZ1 and 2 contribute to color, shape, and depth vision, while TZ3 and 4 have specific roles for UV vision.
关键词： RRID:SCR_014305,vision,ocellus,depth vision,RRID:AB_528479,arthropods,color vision
更新于2025-09-23 15:21:01
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Correlation between laser energetic parameters and magnetic properties of GO laminations under surface treatments with long, short or ultra-short pulsed lasers
摘要： Electromagnetic components mostly incorporate soft magnetic materials used as flux multipliers. Hence, any reduction in iron loss of the magnetic core yields in saving energy. Among the techniques, the local laser treatment is a non-contact method applied for 180° domain refinement (Patri et al. [1]). The present study reassessed the impact of laser treatment on the magnetic properties of grain oriented silicon steels. Various laser pulse widths are used: an ultra-short pulse laser mainly adapted to the ablation process and a long and short pulse durations used for both irradiation and scribing processes [2]. The power loss is measured with a Single Sheet Tester (150 × 150 mm2). Each type of treatment resulted in a power loss reduction of 15–35% at peak induction 1.5 T and frequency 50 Hz. However, only the scribing and the ablation improved also the apparent permeability. In this work, the laser energy parameters are used to estimate the laser impact on the heat affected zone, the groove depth, the induced thermal stress, and on the internal properties of a magnetic behavioral model: static permeability and dynamic magnetization property [3].
关键词： Groove depth,Heat affected zone,GO laminations,Induced thermal stress,Laser treatment,Magnetic properties
更新于2025-09-23 15:19:57
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Stratigraphic characterization of ancient Roman frescos by laser induced breakdown spectroscopy and importance of a proper choice of the normalizing lines
摘要： In order to answer to some specific unsolved questions regarding ancient Roman frescoes from Villa della Piscina, already examined by other spectroscopic techniques, LIBS stratigraphic measurements were performed on the most representative sample fragments. We found that taking into account just the line intensities or applying a single normalization approach based on ratio of the element’s analytical line and a selected transition from a main sample constituent, here of Ca, might produce misleading results of depth profiling by LIBS. During the laser induced ablation, parameters of the detected plasma might change both due to the crater development and different overlaid matrix materials, as in case of heterogeneous painted samples, possibly realized with different techniques. We performed the theoretical simulations to select the pair of Cu I and Ca I lines less sensitive to variations of the plasma temperature in presence of local thermal equilibrium (LTE). However, when using not gated detectors as here, the experimental results showed that only a partial LTE holds. For this reason, the choice of the optimum normalization line must take into account also the energy gap between the excited levels of the species, which energies affect the emission lifetime and consequently, the intensity captured by not gated detectors. In following, to the each element’s analytical line a specific Ca I line was attributed for deducing the relative element distribution in sample. Following this approach and by detecting simultaneously up to 20 elements per laser pulse, it was possible to distinguish clearly by LIBS also thin overpainted layers of similar colour, and to recognize the painting technique used. Through detection of trace and light elements and studies of their correlations with other elements during ablation of on painted layer, in some cases it was possible also to establish the geographical provenance of the material used.
关键词： archaeology,LIBS,quantitative,laser spectroscopy,depth profiling
更新于2025-09-23 15:19:57
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Groove Depth Detection Method Base on the Line Laser Vision Measurement on Cement Concrete Pavement
摘要： The groove depth has a decisive influence on the anti-sliding performance of cement concrete pavement, and it also plays an important role on the noise of cement concrete pavement. Aiming the shortcomings of traditional measurement methods of groove depth detection on the cement concrete pavement, a measurement method base on the structure light vision model was proposed. This method was realized by that the groove depth was obtained by 3D coordinate of the light strip according to the camera model and the structure light plane equation. A new algorithm based on double 2D plane pane target was proposed as the key step of this method.
关键词： groove depth,line laser vision,structure light vision model,cement concrete pavement
更新于2025-09-23 15:19:57
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In situ Measuring Film-Depth-Dependent Light Absorption Spectra for Organic Photovoltaics
摘要： Organic donor–acceptor bulk heterojunction are attracting wide interests for solar cell applications due to solution processability, mechanical ?exibility, and low cost. The photovoltaic performance of such thin ?lm is strongly dependent on vertical phase separation of each component. Although ?lm-depth-dependent light absorption spectra measured by non-in situ methods have been used to investigate the ?lm-depth pro?ling of organic semiconducting thin ?lms, the in situ measurement is still not well-resolved. In this work, we propose an in situ measurement method in combination with a self-developed in situ instrument, which integrates a capacitive coupled plasma generator, a light source, and a spectrometer. This in situ method and instrument are easily accessible and easily equipped in laboratories of the organic electronics, which could be used to conveniently investigate the ?lm-depth-dependent optical and electronic properties.
关键词： light absorption,bulk heterojunction,spectroscopy,organic solar cells,depth pro?ling,organic photovoltaics
更新于2025-09-23 15:19:57